Burner control system

Abstract

A burner control system for controlling the operation of a fuel burner arranged to burn a combination of a supply of fuel and a supply of air is provided. The burner control system is arranged to receive from an exhaust gas analyzer one or more signals, each signal being indicative of the level of an exhaust gas emitted by the fuel burner; receive from a photodetector a signal indicative of a level of electromagnetic radiation output by the flame of the fuel burner; and control at least one of the supply of fuel and the supply of air to the burner based on the one or more signals received from the exhaust gas analyzer and the signal received from the photodetector.

What is claimed is: 
     
       1. A burner control system for controlling the operation of a fuel burner arranged to burn a combination of a supply of fuel and a supply of air, wherein the burner control system is arranged to:
 receive from an exhaust gas analyzer one or more signals, each of the one or more signals being indicative of a level of an exhaust gas emitted by the fuel burner; 
 receive from a photodetector a signal indicative of a level of electromagnetic radiation output by a flame of the fuel burner, wherein the signal received from the photodetector is a single value indicative of a total level of electromagnetic radiation output by the flame; 
 determine a level of oxygen emitted by the fuel burner from the signal received from the photodetector; and 
 control at least one of the supply of fuel and the supply of air to the fuel burner based on the one or more signals received from the exhaust gas analyzer and the signal received from the photodetector. 
 
     
     
       2. The burner control system as claimed in  claim 1 , wherein a signal of the one or more signals received from the exhaust gas analyzer is indicative of the level of oxygen emitted by the fuel burner. 
     
     
       3. The burner control system as claimed in  claim 2 , wherein the burner control system is further arranged to determine the level of oxygen emitted by the fuel burner from a combination of the signal received from the photodetector and the signal indicative of the level of oxygen emitted by the fuel burner received from the exhaust gas analyzer. 
     
     
       4. The burner control system as claimed in  claim 1 , wherein the signal received from the photodetector is indicative of a level of ultraviolet radiation output by the flame. 
     
     
       5. The burner control system as claimed in of  claim 1 , wherein the burner control system is further arranged:
 when in a first operative state, to control at least one of the supply of fuel and the supply of air to the fuel burner based on the signal received from the photodetector; and 
 when in a second operative state, to control at least one of the supply of fuel and the supply of air to the fuel burner based on the one or more signals received from the exhaust gas analyzer. 
 
     
     
       6. The burner control system as claimed in  claim 5 , wherein the burner control system is further arranged to move from the first operative state to the second operative state when the signal received from the photodetector is within a predetermined threshold for a predetermined period of time. 
     
     
       7. The burner control system as claimed in  claim 6 , wherein the burner control system is further arranged to move from the second operative state to the first operative state when the signal received from the photodetector moves outside of the predetermined threshold. 
     
     
       8. The burner control system as claimed in  claim 5 , wherein the burner control system is further arranged to move from the second operative state to the first operative state in response to a change in a level of the supply of fuel to the fuel burner. 
     
     
       9. A burner control system as claimed in  claim 5 , wherein the burner control system is further arranged to move from the second operative state to the first operative state when a signal of the one or more signals received from the exhaust gas analyzer indicates that a level of a first exhaust gas is above a predetermined threshold. 
     
     
       10. The burner control system as claimed in  claim 9 , wherein the first exhaust gas is oxygen. 
     
     
       11. The burner control system as claimed in  claim 5 , wherein the burner control system is further arranged to move from the first operative state to the second operative state when a signal of the one or more signals received from the exhaust gas analyzer indicates that a level of a second exhaust gas has risen above a predetermined level. 
     
     
       12. The burner control system as claimed in  claim 11 , wherein the second exhaust gas is carbon monoxide. 
     
     
       13. A fuel burner arranged to burn a combination of a supply of fuel and a supply of air, comprising:
 an exhaust gas analyzer arranged to generate one or more signals, each of the one or more signals being indicative of a level of an exhaust gas emitted by the fuel burner; 
 a photodetector arranged to generate a signal indicative of a level of electromagnetic radiation output by a flame of the fuel burner; and 
 a burner control system arranged to:
 receive from the exhaust gas analyzer the one or more signals; 
 receive from the photodetector the signal indicative of the level of electromagnetic radiation output by the flame of the fuel burner, wherein the signal received from the photodetector is a single value indicative of a total level of electromagnetic radiation output by the flame; 
 determine a level of oxygen emitted by the fuel burner from the signal received from the photodetector; and 
 control at least one of the supply of fuel and the supply of air to the fuel burner based on the one or more signals received from the exhaust gas analyzer and the signal received from the photodetector. 
 
 
     
     
       14. The fuel burner as claimed in  claim 13 , wherein the photodetector is located in a combustion chamber of the fuel burner. 
     
     
       15. The fuel burner as claimed in  claim 13 , wherein the photodetector is an ultraviolet photodetector. 
     
     
       16. The fuel burner as claimed in  claim 13 , wherein the photodetector is a photodiode. 
     
     
       17. A method of commissioning the fuel burner as claimed in  claim 13 , comprising:
 operating the fuel burner at a plurality of combinations of operational parameters, the operational parameters including at least a level of the supply of fuel and a level of the supply of air to the fuel burner; 
 determining for each of the plurality of combinations of operational parameters the level of oxygen emitted by the fuel burner; 
 recording for each of the plurality of combinations of operational parameters the one or more signals generated by the exhaust gas analyzer and the signal generated by the photodetector; and 
 determining a mapping from the operational parameters, the one or more signals generated by the exhaust gas analyzer and the signal generated by the photodetector to the level of oxygen emitted by the fuel burner. 
 
     
     
       18. The method of commissioning the fuel burner as claimed in  claim 17 , further comprising:
 for each of the plurality of combinations of operational parameters, determining air rich and air lean combinations of operational parameters on either side of the combination of operational parameters; and 
 recording for the air rich and air lean combinations of operational parameters the one or more signals generated by the exhaust gas analyzer and the signal generated by the photodetector.